1. Field of the Invention
The present invention relates to LED lamp technology and more particularly, to a LED lamp having a good heat-dissipating function.
3. Description of the Related Art
Conventional outdoor LED (light-emitting diode) lamps (such as LED street lights) are designed for use in the outdoors. In consideration of the factors of wind, rain and sun and other environmental factors, an outer shell will be necessary to protect the internal light-emitting LED chip and the associated circuit board, preventing rainwater permeation to cause short circuits. Further, during the operation of a LED lamp, much latent heat will be produced. Therefore, conventional LED lamps are generally equipped with a heat sink or like means for quick dissipation of heat. However, because the heat sink and LED chip of a conventional LED lamp are mounted inside the outer shell, the air inside the outer shell cannot be effectively dissipated into the outside air, lowering heat dissipation performance and shortening the lifespan of the LED chip.
Some LED lamp manufacturers make radiation fins on the outer shell in a parallel manner (the radiation fins are of the known design and not indicated in the drawings), increasing the heat dissipation surface area of the outer shell so that the internal high temperature can be released, lowering the temperature of every internal component inside the outer shell. However, the heat dissipation effect of this arrangement is limited.
Further, arranging radiation fins on the outer surface of the outer shell tends to cause a dirt retention problem. According to conventional techniques, the radiation fins are arranged on the outer surface of the outer shell at denser spacings. When used outdoors, rainwater will fall to the gaps between the radiation fins, tree leaves, bird droppings and dust, etc. are likely to be stuck in between the radiation fins. When stayed long, dirt can be consolidated and will not be washed away by rainwater. Dirt can obscure the surfaces of the radiation fins that are disposed in contact with air, lowering the heat dissipation efficiency of the radiation fins.